Data base

Database:

In the broadest sense, a database is anything that stores data. A phone book, for instance, could be considered a database as it stores related pieces of information such as name and phone number. However, in the world of computers, a database usually refers to a collection of related pieces of information stored electronically. Aside from the ability to store data, a database also provides a way for other computer programs to quickly retrieve and update desired pieces of data.

The central concept of a database is that of a collection of records, or pieces of knowledge. Typically, for a given database, there is a structural description of the type of facts held in that database: this description is known as a schema. The schema describes the objects that are represented in the database, and the relationships among them. There are a number of different ways of organizing a schema, that is, of modeling the database structure: these are known as database models (or data models).

The most common model for a database is a relational model. These databases are organized by fields, records, and tables. A field is a single piece of information; a record is one complete set of fields; and a table is a collection of records. With this simple model, just about any relationship between any collection of data can be represented.

Applications of databases

Databases are used in many applications, spanning virtually the entire range of computer software. Databases are the preferred method of storage for large multiuser applications, where coordination between many users is needed. Even individual users find them convenient, and many electronic mail programs and personal organizers are based on standard database technology. Software database drivers are available for most database platforms so that application software can use a common Application Programming Interface to retrieve the information stored in a database. Two commonly used database APIs are JDBC and ODBC.

Examples of use

The largest statistical database maintained by the central authority of statistics in Denmark is called StatBank. The very large database in English is available free-of-charge for all users on the internet. It is updated every day 9.30 am (CET) and contains all new statistics in a very detailed form. The statistics can be presented as cross-tables, diagrams or maps. There are about 2 million hits every year (2006). The output can be transferred to other programs for further compilation.